First Class Mail Stamp prices will increase one cent to .45 on January 22, 2012 for letters. Each additional ounce will remain the same at .20 cents. Postcards will now be .32 cents to mail out. If using Forever stamp,s you may still use those stamps to mail your First Class letters without adding an additional .02 cent stamp to the envelopes within the United States. Remember Forever Stamps are only available for First Class, one ounce letters. If you think your letter weighs more than ounce ounce, be sure to weight it before sending as letters heavier than one ounce will be returned due to lack of postage.
When using Forever Stamps internationally, calcualate the difference between the current First Class rate and the international rate and affix the additional postage to ensure delivery.